erdafitinib + fulvestrant + palbociclib

This is a combination therapy consisting of three agents—erdafitinib, fulvestrant, and palbociclib—investigated for the treatment of estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-), fibroblast growth factor receptor (FGFR)-amplified metastatic breast cancer. - **Erdafitinib** is an investigational oral pan-fibroblast growth factor receptor (FGFR) inhibitor that targets FGFR1–4, blocking aberrant FGFR signaling implicated in tumorigenesis. - **Fulvestrant** is a selective estrogen receptor degrader (SERD) that binds to and accelerates degradation of the estrogen receptor, inhibiting ER-mediated signaling pathways critical for hormone-dependent breast cancer cell survival and proliferation. - **Palbociclib** is an orally available small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which are key regulators of cell cycle progression from G1 to S phase; inhibition leads to cell cycle arrest in ER+ breast cancer cells. The combination aims to overcome resistance mechanisms in advanced/metastatic ER+/HER2-/FGFR-amplified breast cancer by simultaneously targeting hormonal signaling, cell cycle progression, and FGFR-driven oncogenic pathways[1][3][4].